Energy absorber



R. S. QUICK EVAL ENERGY ABSORBER oct. 3, 1939.

4 Sheets-Sheet 1 Filed March 13, 1937 i INVENTORS 2A Y .5. 0U/ C K EOPOl0 A1. EARN/15CH BY fla-,e577- M ,eA-E0 ATTORNEY.

Oct. 3, 1939; R. s. .QUICK Er u.

ENERGY ABSORBER AFiled March 13,- 1937 4 Sheets-Sheet 2 FIE IE FIE`1 Q0ct. 3, 1939. R. s. QUICK er AL 2,174,593

lFrmRGY ABsoRBER Filed March 13, 1937 4 Sheets-Sheet 4 PAY .5. cru/czATTORNEY.

Patented Oct. 3, 1939 UNITED STATES PATENT OFFICE San Francisco, and

Everett M. Breed, San

Mateo, Calif., assignors to The Pelton Water Wheel Company, SanFrancisco, Calif., a corporation of California Application March 13,

4 Claims.

The invention relates to hydraulic energy absorbers of the general typedisclosed in Patent No. 1,539,256, issued May 26, 1925, to FrederickGfeller, and is concerned particularly with energy absorbers for similaruse in hydraulic systems wherein it is desirable to reduce the kineticenergy of the liquid from an amount which is destructive or dangerous toa lower value which can be safely and economically dealt with. Typicalenvironments for energy absorbers` are the outlets of valves, pressureregulators, water wheels, turbines and comparable hydraulic conduits,particularly when such units are very large.

It is an object of our invention to provide an energy absorber which isreadily fab-ricated by ordinary manufacturing yet is of relatively greatslze.

Another object of our invention is to provide an energy absorber whichcan easily be repaired and maintained after initial fabrication andafter installation.

A further object of our invention is to provide an energy absorberhaving a high efficiency.

An additional object of the invention is to provide an energy absorberin which the cost of manufacture and maintenance is relatively low.

A further object of the invention is to provide an energy absorber inwhich cavitation and sudden pressure surges are precluded.

The foregoing and other objects are attained in the embodiments of theinvention disclosed in the drawings, in which- Fig. 1 is a cross-sectionon an axial plane of an energy absorber constructed and installed inaccordance With our invention.

Fig. 2 is a cross-section the planes of which are indicated by the lines2-2 of Fig. l, a portion of the figure being broken away to reduce itssize.

Fig. 3 is an enlarged detail of the contacting portions of the shell anddeflector.

Fig. 4 is a cross-section on an axial plane showing a modified form ofenergy absorber of our invention.

Fig. 5 is a cross-section on an axial plane showing a further modifiedform of energy absorber in accordance with our invention.

Fig. 6 is a half plan of another modified form of energy absorber inaccordance with our invention.

Fig. 'l is a cross-section on an axial plane of the form of energyabsorber shown in Fig. 6.

Fig. 8 is a half cross-section the plane of which is indicated by theline 8-8 of Fig. 7.

Althoughthe energy absorber designed in accordance with our inventionand disclosed here- 1937, Serial No. 130,744

(Cl. 13S-37) to operate at about 420 feet hydraulic head, With 10 anentering velocity of about 164 feet per second and an exit velocity ofabout 25 feet per second, the maximum quantity of Water handled beingabout 1920 second feet, and the equivalent horse power beingapproximately 92,000. Under maximum conditions the axial thrust tendingto dislodge the deiiector is about 620,000 lbs. An energy absorber ofthis size and capacity must be very carefully designed, not only withrespect to the feasibility of manufacture, but likewise with respect tothe difficulty of shipment from the point of manufacture to the point ofinstallation, the difficulty of installation for permanent operation,and the facility of repair and maintenance after a permanentinstallation has been effected. A further factor is to provide a designconsistent with all of these requirements which still is hydraulicallysatisfactory. These various attributes are possessed by the structuresshown herein.

As particularly disclosed in Figs. l, 2 and 3, the energy absorber ofour invention is designed to be attached to the outlet conduit 'I of ahydraulic valve. The valve is represented by a needle 8, locatedcoincident with. the axis 9 of the conduit 1, and is preferablycontoured to formulate a jet Il of Water which may be a solid stream butin the present instance is defmed by inner and outer envelopesrepresented by lines I 2 and I3, indicating that the jet is a hollowcolumn of annular cross-section. The purpose of the energy absorber isto divert this jet and so to control it as to result in a reduction inthe velocity of flow.

To this end the energy absorber 6 comprises an outer shell I4,preferably fabricated of cast steel. Because of the large size of theunit, it is difficult to make such a casting, yet by making the wallsthereof of substantially uniform thickness throughout, successfulcastings can be made. The shell I4 is at one end terminated by anattaching ange I6 receiving fastenings I1 engaging a correspondingflange IB on the conduit 1, and securing the shell in place. From theflange I8 the shell gradually flares radially outward and merges with asomewhat toroidal portion I9 converging into and terminating in adischarge flange 2l. For strengthening the shell I4, on the exteriorthereof there is a plurality of radial ribs 22 extending between theflanges I6 and 2i and at various points having apertures 23 therein forfacilitating manufacture, handling and installation. The described shellforms a continuation of the conduit I, having an especially contouredconfiguration, and defines an upstream inlet aperture 24 and adownstream outlet aperture 2t. The shell I4 itself, being completelyopen in its interior and having substantially uniform walls, can besuccessfully cast with economy even though Very large in size, and iscapable of minute inspection for aws and of careful finishing forsmoothness of hydraulic flow and therefore increased emciency.

In order to divert the flowing jet il, we preferably provide Within theshell I4 a deflector, generally designated 2l. The deflector is a hollowbody, substantially symmetrical about the axis 9, and is locatedcoaxially with the shell I4. Preferably, the major portion of thedeflector is, for cheapness and facility of manufacture, constructed ofcast steel, and We therefore provide the deector with a substantiallyannular body 28 from which extends a plurality of axial and radial arms29, preferably cast integrally with the body 28 and terminating in aring 3I. This ring can be a continuous band, as illustrated in thedrawings, or can be peripherally interrupted, if desired, forfacilitating the casting operation. Under all circumstances the variouswalls of the ring SI and of the body 28, as well as the arms 29, aremade of substantially uniform thickness so that casting is facilitatedand deleterious strains are obviated.

In order to seat the ring 3| in the shell I4, we provide suitablefastening means which are located out of the path of the hydraulicstream II, in a space within the shell unfilled by the flowing hydrauliccolumn. In this way, major interruptions to the flow and deleteriousturbulence are avoided, and freedom to design and provide adequatefastening means is gained. For this reason the shell I4 is provided withan in ternal groove or channel 32, into which a plurality of separatelocking segments 3S are fitted. The segments 33 abut against a lowerflange 34 on the ring 3I and force an upper peripheral flange 36 on thering 3i into abutment with each of a plurality of seats 31 on radiallyarranged ribs 38 within the shell I4. The ring 3| is thereforeaccurately seated within the shell I4 and is clamped in place by thelocking segments 33. These segments themselves are held in place bystuds 39 extending radially outward to engage the shell I4, and arefurther protected by guard segments 4E which in turn are held in theshell by fastening studs 4I.

As a further means for detachably securing the deector within the shellwe provide a plurality of dowel pins 42 partially engaging the upperflange 36 and partially engaging a corresponding flange 43 projectinginwardly from the shell I4. The dowels are primarily for the purpose ofprecluding any rotation of the deiiector within the shell since, undercertain circumstances and with certain types of valve 8, the water jetII has a rotary component causing a helical ow which is effective uponthe arms 29 to impose a torque on the deflector. While in many cases thefrictional lit or clamping action between the removable deiiector andthe shell is adequate toresist any such torque, it is often advisable toprovide a supplementary fastening, such as the dowels 42.

In the fabrication of the deector 2l itself, and in view of the Wear onthe upstream surface thereof due to impingement thereagainst of thehollow jet II, we complement the annulus 28 by an upstream cone 45 theouter surface 4l' of which is preferably faced with a hard,wearresistant material. The cone 46 itself is easily replaceable whenworn, since it is held with a peripheral flange 48 abutting acomplementary flange seat 49 on the annulus 28 by a central bolt 50 andnut 5I. The fastening is located in the hollow center of the jet II, sothat it is not subject to hydraulic stresses, and is additionallyprotected by a cap 52 of conical form which threadedly engages the boltand is provided with sockets 53 for a wrench bar. The bolt 5B ispositioned by engagement with a downstream wear plate 54 which followsthe general contour of the annulus 2li and completes 'the closure of thehollow deiiector. The wear plate 54 is peripherally fianged to receivefastening studs 56 in engagement with a ange seat 5l' on the annulus 23.The path of water fiow or the internal envelope l2 of the dischargingstream is such that the discharging water impinges upon the wear plate54 itself and not upon the annulus 23. Wear upon the deflector isvirtually non-existent except where replaceable wearing parts, such asthe cone 47 and the plate 5d, are situated for` ready replacement.

in the arrange-nient shown in the structure is particularly designed sothat the deflector can be removed from the shell through the inletthereof. in this embodiment the outer shell li is provided with an inletange I2 bounding an inlet opening and is designed for co-operation witha iiange '53 on a hydraulic conduit i4 the characteristics of which aresubstantially the same as those of the conduit l in Fig. l. The shell'l'I has walls of substantially uniform thickness extending to an outletflange T8 which enccmpasses the outlet opening of the shell. Reinforcingribs 'Il extend between the body of the shell and the outlet iiange "ifiand between the body of the shell and the inlet flange l2. The generalcontour of the shell and its fabrication of cast steel are virtually thesame as described in connection with the structure of Figs. 1 to 3.

Adapted to be supported within the inlet opening of the shell is a ring'i9 forming part of a deflector generallydesignated 8E. The ring 'it ispreferably of substantially uniform thickness of cast steel andterminates in a broad flange 82 clamped between the flanges d2 and lf3.The usual fastening means between the flange 'I2 and the flange 'i3effect this clamping action, and, since they also pass through theflange 32, the fastening means also preclude any possibility of rotationof the deector SI within the shell 1I. Extending axially and radiallyfrom the ring i9 are arms 34 joining the annular deiiector body ii andpreferably cast integrally therewith.

To complete the closure of the hollow deflector, the annulus il iscontoured to receive a conical cap nut Si which follows the contour ofthe surface of the body G and engages a bolt downstream face of theannular body 86 and completes the closure of the deflector.

In this arrangement the outer diameter of the deflector body 86 isslightly less than the outer diameter of the ring 19, so that, when theflange 13 and the conduit 14 are removed, the entire deflector assembly8| can be withdrawn from the shell 1| through the inlet opening thereoffor complete replacement or repair. This likewise facilitates access tothe interior of the shell 1| for inspection and repair, access beinggained entirely from the inlet side. Further, if the entire deflector isnot to be repaired, the bottom cover plate 9| and the central cone 81can readily be replaced if desired.

In the modification shown in Fig. 5, the design is similar to that ofthe devices in the preceding figures but has certain specialcharacteristics. In this embodiment the hydraulic conduit flll, whichmay be the outer housing of a relief valve, terminates in a flange |02to which is secured an intermediate adapter section |03 which amounts toa spacing conduit. Ordinarily, the conduit |0| may be removable onlywith difficulty, and the shell |04 of the energy absorber may likewisebe removable with difficulty since customarily the shell is embedded inconcrete. Preferably, however, the adapter section |03 is not soembedded, and, by removing the fastenings which secure the flange |02 tothe adapter |03, and also the fastenings which secure the lower flange|06 of the adapter to the inlet flange |01 of the shell |04, it ispossible to remove the adapter section transversely, leaving an accessspace between the conduit |0| and the shell |04, 'I'his space ispreferably of appropriate dimensions to permit the passage, axially andlaterally, of the deflector |09 which, when installed, is disposedcoaxially with the shell |04.

The deflector preferably comprises an annular body suitably fabricatedand closed by an upstream, central cone ||2 which is connected to thebody by welding ||3, and a downstream closure plate ||4 which also isconnected to the body by welding H6. Extending from the annular hollowbody are radial and axial arms ||1 terminating in a ring ||8 which isprovided with a step ||9 seating within a corresponding step ring |2|joined to the shell |04 by a plurality of radial arms |22. Preferably,the rings |2| and ||8 are located outside of the outer envelope |23 ofthe hydraulic jet |24 so that they in no wise interfere with thesmoothness of hydraulic flow through the structure. When the adaptersection |03 is removed, the deflector |69 can be passed through theinlet opening of the shell |04 into the space left by removal of theadapter section |03 and can then be entirely removed transversely of theconduit |0| and the shell |04 for replacement or repair. In someinstallations it is not feasible to remove the spacing conduit |03, butthe deector |09, and especially the ring ||8, are of sufficiently smalldiameter that the deflector can be passed axially through the spacingconduit and into the conduit |01. In instances wherein the conduit |0|is the housing of a valve, the interior mechanism of the valve flrst isremoved to allow axial passage of the deilector through the conduit 0|for inspection and repair.

As disclosed in Figs. 6 to 8, inclusive, there is provided an energyabsorber in which the outer shell 3| is similar to that shown in Fig. 1and includes attaching flanges |32 and |33 and an interposed, somewhattoroidal portion |34. Beneath the attaching flange |33 there is provideda circular seat |36 for a ring |31 included in a deflector |38 locatedcoaxially within the shell |3I. A circular internal flange |39 integralwith the shell also serves as an abutment for the ring |31, which isheld against the shell |3| by suitable fastenings, such as studs |4|.

The ring |31 and the shell between the flange |39 and the seat |36together define an annular conduit |42 communicating with the exteriorthrough a duct |43 and serving as a manifold for hollow arms |44supporting the hollow delector body |38. The deflector is completed by alower wear plate |46, held in place by studs |41, and an upper wear cone|48 hel-d by a stay |40 engaging the lower plate |46 and provided with anut |5| abutting the cone |48. A cap |52 also engages the stay andprovides a smooth terminus for the cone |48.

As a special attribute of this design, the deflector body |38 on itslower face, and the wear plate |46, are provided with a plurality ofapertures |53 establishing communication between the interior of thedeflector |38 and the interior of the shell |35. In operation, the flowof water through the energy absorber induces the flow of air into theduct |43, through the conduit |42 an-d the arms I 44 to the body |38,from whence the air discharges through the apertures |53 to mix with andbecome entrained with the flowing water. This admixture of air preventsor destroys areas of high vacuum within the conduit which would causecavitation accompanied by heavy pounding and severe pressure surges.

This design also illustrates a feature of construction which can beapplied to the other embodiments, in that a major part of the deflectoris sectionalized so that it can be assembled and -disassembled withinthe shell |3| and removed through either opening. Preferably, the ring|31 and related members are parted in several places, for instance sixplaces defined by equidistant radial planes. The separate parts areprovided With appropriate fastening flanges |56 and securing devices|51.

We claim:

1. An energy absorber comprising a shell, a deflector within said shelland together therewith providing a tortuous hydraulic path, means fordirecting hydraulic fluid flowing in said path to fill only part of saidshell, and means in an unfilled part of said shell for removablyattaching said deflector to said shell.

2. An energy absorber comprising a shell for confining the flow ofhydraulic fluid, a hollow deflector Within said shell, and means foradmitting air to the interior of said shell through said deflector.

3. An energy absorber comprising a` shell for confining the flow ofhydraulic fluid, a deflector within said shell, and means for releasingair into said shell adjacent the lower face of said deilector.

4. An energy absorber comprising a hydraulic conduit, an enlarged shellcoaxial with said conduit and contoured to provide a radially inwardhydraulic flow, a deflector disposed coaxially within said shell, andmeans arranged concentrically within said shell and out of saidhydraulic flow for detachably securing said deflector thereto.

RAY S. QUICK. LEOPOLD M. KARNASCH. EVERE'I'I M. BREED.

